On Mon, Oct 15, 2012 at 3:59 PM, houmanb <houman@xxxxxx> wrote: > Dear all, > We have a DB containing transactional data. > There are about *50* to *100 x 10^6* rows in one *huge* table. > We are using postgres 9.1.6 on linux with a *SSD card on PCIex* providing us > a constant seeking time. > > A typical select (see below) takes about 200 secs. As the database is the > backend for a web-based reporting facility 200 to 500 or even more secs > response times are not acceptable for the customer. > > Is there any way to speed up select statements like this: > > SELECT > SUM(T.x), > SUM(T.y), > SUM(T.z), > AVG(T.a), > AVG(T.b) > FROM T > GROUP BY > T.c > WHERE > T.creation_date=$SOME_DATE; > > There is an Index on T.c. But would it help to partition the table by T.c? > It should be mentioned, that T.c is actually a foreign key to a Table > containing a > tiny number of rows (15 rows representing different companies). > my postgres.conf is actually the default one, despite the fact that we > increased the value for work_mem=128MB it might help a little bit or a lot -- it depends on the plan. I'd also advise raising shared buffers to around 25% of ram for queries like this. what's your server load look like while aggregating -- are you storage or cpu bound? which ssd? how much data churn do you have? merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
